JP2004335977A - Electromagnetic shield member and shield device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow an electromagnetic shield member and a shield device to keep good performance, which is excellent in an electromagnetic shield function without damaging a hermetic sealing function at a joint, in a long term. <P>SOLUTION: The electromagnetic shield member 20, which is mounted in a recess channel 13 located in one member 12 and abuts against the other member 14 at a position where a pair of members 12, 14 detouchably face each other to perform the electromagnetic function, is made up of a conductive material, and is equipped with a conductive outer member 50, which has a pair of opening/closing pieces 51, 51 whose one ends 56 are joined and the other ends face openably/closably at a space each other in a sectional profile, and an elastic core member 40, which is sandwiched between the opening/closing pieces 51, 51 of the conductive outer member 50 and is easily elastically-deformed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electromagnetic shielding material and a shielding device, and more particularly, to an electromagnetic shielding material used in a place where electromagnetic shielding is required, such as a plasma processing device, and a shielding device using such an electromagnetic shielding material And are targeted.
[0002]
[Prior art]
2. Description of the Related Art In a technical field such as a semiconductor manufacturing technique or a thin film forming technique, in a processing apparatus which performs an etching process, a sputtering process, a CVD process, or the like, a strong electric field or an electromagnetic wave may be generated in a processing chamber. For example, in a plasma processing apparatus, a strong electric field is applied to a processing gas supplied into a processing chamber in a vacuum state to generate plasma, and various processing is performed on an object to be processed by the plasma flow.
Usually, the processing chamber of such a processing apparatus is closed by closing an opening of a container body having a container shape with a lid. By removing the lid as needed, the inside of the processing chamber can be inspected and cleaned. The facing portion between the lid and the container body is hermetically sealed with an O-ring or the like so that external air does not enter or internal plasma gas leaks. Further, the container body and the lid are electrically connected to each other so that the processing chamber is electromagnetically shielded from the external environment so that electromagnetic waves generated during the processing do not leak to the outside.
[0003]
In Patent Literature 1, an O-ring that performs a hermetic sealing function is disposed at a joint between a container body and a lid of a vacuum container, and an electromagnetic shield member made of a tilted coil spring is provided on the outer peripheral side of the O-ring. An arrangement technique has been proposed. It is said that an inclined coil spring in which a coil material is wound obliquely is easily deformed, so that the effect of hermetic sealing by an O-ring is hardly impaired. Patent Literature 1 also describes, as a description of the related art, an electromagnetic shield member having a structure in which a string-like elastic body made of rubber or the like is inserted inside a cylindrical mesh conductor.
[0004]
[Patent Document 1]
JP-A-2002-164885
[0005]
[Problems to be solved by the invention]
In the above-mentioned conventional technology, there is a problem that the electromagnetic shielding function is insufficient, the durability is poor, and the hermetic sealing function is deteriorated.
In the technique of Patent Document 1, the contact between the inclined coil spring and the members on both sides occurs only at the apex of the spiral coil wire. Since it is only intermittent point contact, electrical contact with the members on both sides is likely to be insufficient, and the contact resistance is large and electrical conduction is poor, so that the effect of electromagnetic shielding may not be sufficiently achieved.
In order to achieve a sufficient electrical conduction or electromagnetic shielding function only by intermittent point contact, it is necessary to increase the elastic repulsive force of the inclined coil spring to increase the contact pressure with the members on both sides. However, when the lid is repeatedly opened and closed for a periodical cleaning work in the processing chamber, the members on both sides that come into point contact with the inclined coil spring collide with or are rubbed with the inclined coil spring. As a result, fine abrasion powder is generated, and this fine powder (particles) contaminates a processing chamber requiring a high-grade clean environment. Such particles impair the quality performance of the semiconductor product and lower the production yield. The work of removing particles takes time and effort, delays the start of the processing work, and greatly impairs work efficiency.
[0006]
The material of the gradient coil spring is a relatively hard material such as a spring steel material, whereas the material of the container body and the lid is a relatively soft material such as aluminum. The material of the container body and the lid is easily shaved. The above problem becomes more pronounced as the elastic repulsion of the inclined coil spring is increased in order to enhance the electrical conductivity.
Moreover, even if the inclined coil spring can be easily deformed than a normal cylindrical coil spring, it is considerably harder than a rubber material or the like, so that the air-tight sealing function of the O-ring provided separately from the electromagnetic shield member is impaired. There is also the problem that If the electromagnetic shield member cannot be easily deformed, the compressive force applied to the parallel O-rings will be weakened and the deformation will be insufficient, and the elastic repulsive force accompanying the deformation will also be weakened, and the hermetic sealing function will be reduced. is there.
[0007]
In the combination structure of the tubular mesh conductor and the rubber string-like elastic body described in Patent Document 1 as a conventional technique, the tubular mesh conductor is easier to deform than the coil spring. There is an advantage that the stopping function is not easily damaged. However, as described in Patent Document 1, the string-like elastic body exposed to the internal environment of the processing chamber deteriorates with time and loses elasticity, and the force for pressing the tubular mesh conductor against the members on both sides is reduced. As a result, the electrical conductivity decreases, and the intended electromagnetic shielding function is impaired.
Further, in the technique of Patent Document 1, since the electromagnetic shield member is arranged on the outer peripheral side of the O-ring that functions to prevent airtightness, plasma gas or the like generated in the processing chamber comes into contact with the rubber material forming the O-ring. As a result, the rubber material is quickly deteriorated, and the O-ring must be replaced in a short period of time.
[0008]
An object of the present invention is to provide an electromagnetic shielding material which is excellent in an electromagnetic shielding function and which can maintain good performance for a long period of time without impairing a hermetic sealing function of a joining portion.
[0009]
[Means for Solving the Problems]
The electromagnetic shielding material according to the present invention is an electromagnetic shielding material which is mounted on a concave groove provided on one member and abuts on the other member to perform an electromagnetic shielding function at a place where a pair of members face each other so as to be able to come and go. A conductive covering material made of a conductive material, having a pair of opening and closing pieces facing one another in a sectional shape, one end of which is connected and the other end of which is openable and closable, between the opening and closing pieces of the conductive covering material; Between the elastic core material that is easily elastically deformed
Is provided.
[A pair of members]
The part where the electromagnetic shielding material is used and the pair of members face each other so that they can come and go is the mating surface of the container body and the lid, the contact surface between the valve body and the valve seat of the valve structure, and the various processing chambers. This is a structural part of a mechanical device that performs a contacting / separating operation in which a pair of members such as a contact surface between an opening and an opening / closing lid are brought into contact with each other to be sealed or separated from each other and opened.
[0010]
In particular, it is a structural part that requires an electromagnetic shielding function to prevent the electromagnetic wave from leaking through the facing portion while electrically connecting the members in a state where the members are brought into contact with each other and closed.
Specifically, in a semiconductor manufacturing apparatus for manufacturing a semiconductor device such as an integrated circuit element, a facing portion between a container body and a lid constituting a processing chamber for performing various processes on a semiconductor wafer may be mentioned.
Semiconductor manufacturing apparatuses include a plasma processing apparatus, an ion processing apparatus, a CVD apparatus, a PVD apparatus, a dry etching apparatus, and the like, and an apparatus having a plurality of processing functions. The present invention is applied to a processing apparatus which may generate a high-voltage electric field in a processing chamber or generate electromagnetic waves. The present invention is also applied to an apparatus in which plasma gas, ionized ions, corrosive gas, and the like are supplied into the processing chamber or are generated inside.
[0011]
The opening / closing valve portion of the opening through which the semiconductor wafer to be processed enters and exits the semiconductor manufacturing apparatus, the attachment portion of the inspection port and the observation port, and the like are also places where the electromagnetic shielding material is attached.
In addition to a semiconductor manufacturing apparatus, the present invention is applied to a processing apparatus having a common structure for manufacturing various electronic elements and precision parts and performing various processes.
[Electromagnetic shield mounting structure]
At the mounting position of the electromagnetic shielding material, a concave groove is provided on one of the members. The concave groove usually has a rectangular shape, and has dimensions corresponding to the width and height of the electromagnetic shielding material. The inner wall of the groove may be inclined or curved. The bottom surface of the groove may be flat or inclined, or may have steps or irregularities.
[0012]
In the case of the processing chamber or the valve portion of the plasma processing apparatus, an annular groove surrounding the opening is provided. The ring shape depends on the shape of the opening, but may be a shape including a curved portion such as a circle, an oval, and an ellipse, in addition to a polygon such as a rectangle.
A part of the electromagnetic shielding material protrudes above the upper edge of the groove when housed in the groove. This amount of protrusion serves as a margin.
A portion of the other member having no concave groove, which comes into contact with the electromagnetic shield material, is usually flat. It may have shallow grooves, irregularities, or slopes.
At least a portion of the pair of members that comes into contact with the electromagnetic shielding material is made of a conductive material so that electromagnetic energy can pass therethrough. Specifically, it is desirable to be made of a conductive metal material such as steel. A conductive coating can be applied to the surface of the insulating material, or a conductive material can be added to the insulating material to impart conductivity. A ground wire can be connected or grounding can be performed.
[0013]
The electromagnetic shielding material can be installed over the entire length of the groove. An annular electromagnetic shielding material can be attached to the annular groove. However, if the required electromagnetic shielding function is achieved, there is a case where the electromagnetic shielding material is merely attached to only a part of the concave groove. The electromagnetic shielding material may be intermittently attached to a plurality of locations in the annular groove.
(Conductive sheath material)
It is made of a conductive material and performs an electromagnetic shielding function. In addition, it also has a function of protecting the elastic core material.
[0014]
As the conductive material, a material which is hardly eroded by a plasma gas or a corrosive gas is preferable. A material having excellent elastic deformability is preferable. It is preferable to use a material that does not easily stick to or adhere to the member having the concave groove and the mating member. Those excellent in mechanical strength and friction durability are preferable. As a specific material, stainless steel such as SUS304, SUS316, and SUS316L can be used. In addition, titanium alloys, aluminum alloys, copper alloys, Hastelloy alloys, and Inconel alloys can also be used. The surface of the conductive material may be subjected to a surface treatment such as coating.
As for the thickness of the conductive covering material, the thinner the better, the easier it is to be deformed by the elastic repulsion of the elastic core material. If the thickness is too thin, problems such as distortion may easily occur when joining and joining by welding. The preferred thickness varies depending on the material of the conductive covering material, but is usually 0.05 to 0.20 mm.
[0015]
(Opening and closing piece)
The conductive covering material is composed of a pair of opening and closing pieces. One end of the pair of opening and closing pieces is connected in the cross-sectional shape, and the other end faces openably and closably at an interval. Opening / closing means that the facing distance between the opening / closing pieces can be increased or decreased.
The opening / closing piece does not require much elastic opening / closing function. This is because the elastic core material mainly performs the elastic opening / closing operation of the opening / closing piece. It is desirable that the opening / closing piece has a characteristic that it can sufficiently bend and deform even with a relatively small force.
The pair of opening / closing pieces can be formed in a generally thin plate shape, such as a V-shape, a U-shape, or a U-shape, so that the deformability can be enhanced. An elastic core material is accommodated between the pair of opening / closing pieces. The pair of opening / closing pieces may be formed by bending one plate material, or may be formed by joining two plate materials at one end. It is easier to smoothly open and close with less force by joining two plate members. The pair of opening / closing pieces usually have mutually symmetric shapes, but those having a partially different shape may be combined.
[0016]
As the shape of the opening / closing piece, one having an arc-shaped portion, an extended portion, and a connecting portion can be used.
<Arc part>
The arc-shaped portion smoothly abuts on the elastic core material and the members present on both sides of the opening / closing piece, and locally between the elastic core material and the opening / closing piece, and between the opening / closing piece and the members on both sides thereof. The generation of excessive stress can be prevented. It is unlikely that the opening / closing piece scrapes and scrapes the members on both sides. The electrical contact between the opening / closing piece and both side members can also be improved.
The arc-shaped portion preferably has an arc shape with a curvature R1 larger than the radius of curvature of the elastic core material at a contact point with the elastic core material. In the case of an elastic core having a circular cross section, 1/2 of the diameter D1 of the elastic core is the radius of curvature of the elastic core. The radius of curvature R1 of the arc portion can be set to 70 to 100% of the radius of curvature D1 of the elastic core material. If the radius of curvature R1 of the arc portion is too small, the elastic core material is shaved when the conductive outer cover material rubs against the elastic core material, and particles are easily generated. If the radius of curvature R1 of the arc-shaped portion is sufficiently large, when the conductive covering material comes into contact with the concave groove of the member to which the electromagnetic shielding material is attached and the surface of the mating member, both of the two members are brought into contact at the outer edge of the contact region. The surfaces gradually come into contact with each other, and the contact pressure gradually increases toward the center. As a result, it is possible to effectively prevent the member against which the conductive covering material comes into contact from being damaged or scraped off. If the radius of curvature R1 of the arc-shaped portion is too large, the size of the conductive covering material becomes too large.
[0017]
The arc-shaped portion desirably covers the entire elastic core material in the width direction. In particular, in the state where the elastic core material is housed, it is desirable to extend the edge of the arc-shaped portion, which is on the opening side of the opening / closing piece, on the side opposite to the connecting portion, to the outside of the side end of the elastic core material.
<Extension>
The extension portion extends in parallel with one end of the arc-shaped portion in contact with the extension portion of the opening / closing piece on the other side. The extended portions of the pair of opening and closing pieces are arranged so as to form one straight line. The presence of the extension allows the pair of opening and closing pieces to open and close smoothly, and when a force is applied in the direction to close the opening and closing pieces, deformation in the direction to close smoothly without generating excessive stress locally. it can. Excessive deformation stress can be prevented from being generated only in the connecting portion. The longer the length L1 of the extension portion, the better the opening / closing operation of the opening / closing piece can be performed and the stress of the connecting portion can be reduced, but the overall width of the conductive outer cover material and the electromagnetic shield material increases. The appropriate length L1 varies depending on the application and required performance, but can be set to 20 to 40% of the total width L0 in the cross section of the conductive jacket material.
[0018]
If the extension portion and the arc-shaped portion are connected by a smooth curve, the arc-shaped portion can be smoothly deformed from the extension portion and a large stress is hardly generated locally. The radius of curvature R2 of the portion connecting the extension and the arc can be set to 70 to 80% of the radius of curvature R1 of the arc.
<Connecting part>
The connection portion is connected to the opening / closing piece on the other side at one end of the extension portion. As the connecting means, welding can be adopted. As a welding method, arc welding, Tig welding, or the like can be applied. These welding methods provide good electrical continuity between the opening and closing pieces in the connection portion, and also facilitate deformation of the extension portion. It is a preferred connection means. As an electromagnetic sealing material used in a semiconductor device manufacturing apparatus, Tig welding using an inert gas is preferable. In addition, appropriate joining means can be adopted from joining means of ordinary materials in accordance with the material of the opening / closing piece.
[0019]
<Face spacing>
The facing distance between the pair of open / close pieces in the conductive covering material may be set in accordance with the size of the elastic core material. In the state where the elastic core material is housed, a force in the compression direction may be applied to the elastic core material, or the elastic core material may be freely movable inside the conductive covering material. The application of a light compressive force facilitates the positioning of the elastic core material.
The work of pushing the elastic core material into the conductive outer cover material is easier to perform as the gap G between the tips of the arc portions increases. If the interval G is too wide, the elastic core material accommodated inside the conductive jacket material may be protruded from between the open / close pieces during handling or use. Specifically, the interval G can be set to 50 to 80% of the length D1 of the elastic core material.
[0020]
(Elastic core material)
It is sandwiched between the opening and closing pieces of the conductive covering material, and is easily elastically deformed. It has a string shape following the length of the electromagnetic shielding material.
Basically, the same material and structure as those of a normal O-ring can be adopted.
The material of the elastic core material is preferably a material that can withstand the environment of the mounting location and exhibit good elastic repulsion. In an environment where a plasma gas exists, a material having high plasma resistance is preferable. Depending on the use environment, heat resistance, corrosion resistance, light resistance, and the like are required. Since the elastic core material is covered with the conductive jacket material, it is rarely directly exposed to plasma gas, etc., but in order to withstand plasma gas, etc. that exceeds the conductive jacket material or passes through gaps. It is desirable to have the above-mentioned characteristics.
[0021]
Specific materials include fluorine rubber and silicone rubber. In particular, it is preferable to use a perfluorinated fluororubber which is completely fluorinated or a fluororubber having improved plasma resistance which is known for semiconductor manufacturing equipment. For example, a fluorine rubber O-ring surface-treated with an organosiloxane-based monomer or a fluorine-based monomer disclosed in JP-A-11-172027 can be used.
As the cross-sectional shape of the elastic core material, the same circle as a normal O-ring can be adopted. An elliptical shape, an elliptical shape in which the circle is slightly deformed, and a shape in which the corners of a polygon are rounded can also be adopted.
To assemble the electromagnetic shield material, the opening and closing piece of the conductive outer cover material may be elastically deformed and opened, and an elastic core material may be inserted therebetween. After disposing the elastic core material between the open / closed pieces that have been opened in advance, the openable / closed pieces can be sandwiched from both sides to reduce the gap therebetween. In the assembled state of the electromagnetic shielding material, it is preferable that the gap G on the distal end side of the opening / closing piece is smaller than the diameter D1 of the elastic core material so that the elastic core material does not fall off the conductive outer material.
[0022]
[Shielding device]
The electromagnetic shielding material basically performs only the electromagnetic shielding function, and the hermetic sealing function is not so high. Therefore, when a sufficient performance is required also for the hermetic sealing function, a shield device in which the hermetic sealing function is added to the electromagnetic shielding function by the electromagnetic shielding material can be configured.
The shield device is disposed at a facing position where the pair of members can freely contact and separate from each other, as in the case where the electromagnetic shield material is used alone.
A first concave groove and a second concave groove are provided at the facing portion.
[0023]
An airtight shielding material is mounted in the first concave groove provided in any one of the members. The hermetic shield member is in contact with the other member to hermetically seal the inside and outside of the first groove.
The second groove is provided on one of the members outside or inside the first groove. The above-described electromagnetic shield material is mounted in the second concave groove. The electromagnetic shield material is in contact with the other member to electrically conduct the members on both sides of the electromagnetic shield material, and electromagnetically blocks the inner space and the outer space of the second groove.
Regarding the arrangement of the electromagnetic shielding material and the hermetic shielding material, it is desirable to arrange the electromagnetic shielding material on the side that comes into contact with the plasma flow, the electromagnetic wave, the corrosive gas or the like first. For example, in the case where the cover is provided at a position facing the processing chamber and the lid of the plasma processing apparatus, an electromagnetic shielding material is disposed closer to the inside of the processing chamber, and an airtight shielding material is disposed closer to the outside of the processing chamber. . With this configuration, the conductive covering material of the electromagnetic shielding material can prevent the passage of the plasma and the corrosive gas, and can effectively prevent the deterioration and damage of the airtight shielding material.
[0024]
As a result, both functions of the hermetic sealing by the hermetic shield material and the electromagnetic shielding by the electromagnetic shield material can be effectively combined, and both functions can be exhibited well.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
[Plasma processing equipment]
FIG. 1 shows a schematic structure of a plasma processing apparatus 10 having a shield structure using an electromagnetic shield material.
The plasma processing apparatus 10 includes a container body 12 that forms a container-like processing chamber, and a lid plate 14 that closes an upper surface opening of the container body 12. Electrodes 16 and 18 are arranged on the container body 12 and the lid 14, respectively. Wirings 17 and 19 connected to a power supply are connected to the electrodes 16 and 18, respectively. In addition, the ground wire 11 is connected to the container body 12. A high-frequency voltage or the like can be applied to the electrodes 16 and 18. Although not shown, the container body 12 is also provided with a vacuum exhaust pipe, a processing gas supply pipe, and the like.
[0026]
A workpiece W such as a semiconductor wafer is disposed on the lower electrode 16 and a voltage is applied to the electrodes 16 and 18 to generate plasma in the container body 12. Plasma processing such as plasma CVD is performed.
In such a plasma processing apparatus 10, a shielding structure including an electromagnetic shielding material 20 and an airtight sealing material 30 is provided at a joint between the container body 12 and the lid 14.
The hermetic sealing material 30 prevents the vacuum state in the container main body 12 from being damaged by the intrusion of air from the outside, and prevents the processing gas and plasma gas in the container main body 12 from leaking out of the container main body 12. I do.
[0027]
The electromagnetic shielding member 20 prevents an electromagnetic wave or a strong electric field generated in the container body 12 from leaking out of the container body 12. When a process is performed by applying a voltage to the electrodes 16 and 18, electric charges are accumulated in the lid 14 to which the ground line 11 is not connected (charge-up), and a gap is formed between the lid 14 and the container body 12. Although a spark may be generated, the electromagnetic shielding material 20 prevents the above-described spark from being generated by releasing the electric charge accumulated in the lid 14 from the container body 12 to the ground wire 11.
The joint between the opening of the container body 12 and the lid 14 is annularly formed along a flange portion provided on the outer periphery of the container body 12. The electromagnetic shield member 20 and the hermetic sealing member 30 are also arranged annularly along the outer periphery of the container body 12.
[0028]
[Structure of electromagnetic shielding material]
FIG. 2 shows a cross-sectional structure of the electromagnetic shielding member 20.
The electromagnetic shield member 20 includes a conductive outer cover member 50 and an elastic core member 40.
The elastic core member 40 has a string shape as a whole, has a circular cross section with a diameter D1, and is formed of an elastic material having plasma resistance and excellent elastic resilience, such as fluororubber.
The conductive covering material 50 is formed of a stainless steel thin plate such as SUS304, and is constituted by a pair of upper and lower opening and closing pieces 51, 51 symmetrical to each other. The opening / closing pieces 51, 51 are arranged so as to cover the elastic core member 40 from above and below.
[0029]
The opening / closing pieces 51 have an arc-shaped portion 52, an extension portion 54, and a connecting portion 56.
The arc-shaped portions 52 are arranged above and below the elastic core member 40 and have an arc shape. The radius of curvature R1 of the arc-shaped portion 52 is set to be slightly larger than the radius of curvature (1/2 of the diameter D1) of the elastic core material 40. The arc-shaped portion 52 and the elastic core material 40 are in contact at or near the upper and lower diametrical ends of the elastic core material 40. Along the axial direction of the elastic core material 40, the contact area is continuous in the form of a band at the top and bottom.
One ends of the arc-shaped portions 52 are opposed to each other with an interval G therebetween. This interval G is slightly smaller than the diameter D1 of the elastic core material 40. The elastic core member 40 sandwiched between the upper and lower opening / closing pieces 51, 51 does not easily come out of the gap G.
[0030]
The other end of the arc portion 52 is connected to the extension portion 54. The extension portion 54 extends in parallel with the upper and lower opening / closing pieces 51, 51 in contact with each other for a length L <b> 1. Since the extensions 54 are not joined, they can be deformed independently. The connecting portion between the extension portion 54 and the arc-shaped portion 52 is smoothly connected by a curve having a radius of curvature R2.
The end of the extension 54 is a connecting portion 56 in which the upper and lower extensions 54, 54 are integrally joined by welding. The connecting portion 56 has a shape slightly expanded from the extension portions 54, 54.
The upper and lower opening / closing pieces 51, 51 connected by the connecting portion 56 can be opened and closed elastically up and down with the connecting portion 56 as a base point due to the elastic deformability of the material. When the opening / closing pieces 51, 51 are opened, the gap G between the arc-shaped portions 52, 52 is widened, so that the elastic core member 40 can be easily taken in and out. When the opening / closing pieces 51, 51 are opened, the extended portions 54, 54 are in a state of being parallel and in contact with each other, and the ends of the arc-shaped portions 52, 52 are separated and inclined in opposite directions. When there is no longer any force to open the opening / closing pieces 51, 51, the opening / closing pieces 51, 51 close elastically. The arc-shaped portions 52, 52 sandwich and fix the elastic core material 40 from above and below. Further, when a force is applied in a direction to close the opening / closing pieces 51, 51, the arc portions 51, 51 are deformed in a state where the extension portions 54, 54 are in contact with each other. Deformation force is absorbed from the arc portions 51, 51 by the extension portions 54, 54, and no large deformation force is applied to the connecting portion 56.
[0031]
[Use of electromagnetic shielding material]
<Attached state>
FIG. 3A shows a state in which the electromagnetic shield member 20 is mounted on the container body 12 of the plasma processing apparatus 10. The hermetic sealing material 30 is also attached to form a shield structure.
Two annular concave grooves 13 and 15 that are adjacent to the inside and outside are formed over the entire periphery of the opening upper end surface of the container body 12. The inner annular groove 13 near the inside of the container body 12 has a flat rectangular shape having a cross-sectional shape wider than the depth, and the electromagnetic shielding material 20 is attached thereto. The outer annular groove 15 close to the outside of the container body 12 has a rectangular cross-sectional shape that is closer to a square with a smaller width than the annular groove 13.
[0032]
The electromagnetic shielding member 20 mounted in the annular groove 13 has a width L0 slightly smaller than the inner width of the annular groove 13, and the arc-shaped portions 52, 52 of the conductive jacket material 50 are located on the outer peripheral side of the annular groove 13. , The connecting portion 56 is disposed on the inner peripheral side. The height of the electromagnetic shield member 20 is slightly larger than the depth of the annular groove 13, and a part of the electromagnetic shield member 20 protrudes above the annular groove 13.
The O-ring 30 mounted on the annular groove 15 is narrower than the inner width of the annular groove 15 and higher than the depth of the annular groove 15.
The lower surface of the lid 14 that covers the upper end surface of the opening of the container body 12 is flat.
[0033]
<Use condition>
As shown in FIG. 3B, the lid body 14 is put on the container main body 12, and the lid body 14 is press-fitted by means such as bolting and fixed.
The electromagnetic shielding member 20 pressed by the lid 14 is deformed so that the vertical width of the opening / closing pieces 51 of the conductive coating material 50 is reduced. Along with the deformation of the opening / closing pieces 51, the elastic core material 40 is deformed so that the cross section is crushed from circular to flat. A repulsive force is generated in the elastically deformed elastic core member 40, and the opening / closing pieces 51, 51 are pressed against the bottom surface of the annular groove 13 and the bottom surface of the lid 14. With this pressing force, a good electrical connection state is formed from the lid 14 to the container main body 12 via the conductive covering material 50, and a high electromagnetic shielding function is exhibited.
[0034]
The contact between the annular groove 13 and the lid 14 of the container body 12 and the conductive covering material 50 occurs along a ridge line which is continuous in the length direction of the conductive covering material 50 at the vertex of the arc-shaped portion 52 of the opening / closing piece 51. . Actually, since the material on both sides is deformed at the contact point, a strip-shaped contact area having a constant width on the left and right across the ridge is formed. In particular, since the arc-shaped portion 52 is smoothly deformed so as to have a large radius of curvature, not only the ridge of the arc-shaped portion 52 but also a sufficient area including both side portions of the ridge, the cover 14 and the annular concave groove 13 Can contact. As described above, since a large contact area is obtained, the state of electrical conduction from the annular groove 13 of the container main body 12 to the lid 14 by the conductive covering material 50 is good. Since the contact area is large, even if the contact pressure is relatively small, the contact resistance is sufficiently reduced.
[0035]
On the inner peripheral side of the contact position between the arc-shaped portion 52 and the lid 14 and the annular concave groove 13, the upper and lower opening / closing pieces 51, 51 connected by the connecting portion 56 completely cover the elastic core member 40.
As shown by the white arrow and the dashed arrow in FIG. 3B, plasma gas, corrosive gas, and the like existing in the container body 12 pass through the gap between the lid 14 and the container body 12 to form the annular groove 13. Even if it invades the inside, further intrusion is prevented by the conductive covering material 50. Leakage to the inner side and outer peripheral side of the opening / closing piece 51 beyond the conductive jacket material 50 is suppressed. The elastic core member 40 is prevented from being directly exposed to the plasma gas or the like and deteriorated. A large amount of plasma gas, heat flow, corrosive gas and the like are prevented from reaching the O-ring 30.
[0036]
The O-ring 30 is deformed and flattened so as to be crushed between the lid 14 and the bottom surface of the annular groove 15. The elastic repulsion of the O-ring 30 strongly hermetically seals the space between the lid 14 and the bottom surface of the annular groove 15. The gas in the container body 12 does not leak to the outside, and the degree of vacuum of the container body 12 is not impaired.
It should be noted that the elastic repulsion caused by the deformation of the electromagnetic shield member 20 is basically determined by the elastic repulsion of the elastic core member 40 and is not so large, so that the hermetic sealing function of the O-ring 30 due to the elastic repulsion is impaired. Never. Even if there is some gas leaking from the inside of the container body 12 beyond the electromagnetic shield member 20, the sealing can be reliably performed at the position of the O-ring 30. Conversely, even if air or the like attempts to enter the container body 12 from the external environment, it is reliably prevented at the position of the O-ring 30. It is not necessary to provide the electromagnetic shielding member 20 with a very high sealing function. The elastic repulsive force of the electronic shield material 20 is sufficient to ensure electrical conductivity, and a high degree of hermetic sealing is not required.
[0037]
When the lid 14 is removed from the container main body 12 for internal inspection or cleaning of the processing apparatus 10, the O-ring 30 is restored to its original shape by its elastic restoring force. The electromagnetic shield member 20 is restored to the original shape by the elastic restoring force of the elastic core member 40. Therefore, when the lid 14 is attached to the container body 12 again, the hermetic sealing function by the O-ring 30 and the electromagnetic shielding function by the electromagnetic shielding material 40 are exhibited as well as the first mounting. Even if the cover 14 is repeatedly attached and detached, the electromagnetic shielding function of the electromagnetic shielding material 40 does not decrease.
When the cover 14 is put on the container body 12, the bottom surface of the cover 14 collides with the conductive outer cover material 50 of the electromagnetic shield material 40. At this time, the flat bottom surface of the cover 14 52. Since the contact area gradually expands from the apex of the arc-shaped portion 52 to the periphery in a state where the surfaces on both sides in contact are inclined from the center to the periphery, the bottom surface of the lid 14 colliding with the arc-shaped portion 52 is locally excessively large. No stress is generated, scratched, rubbed or scraped off. No harmful particles are generated. Needless to say, since the pressure is smoothly pressed even between the bottom surface of the annular groove 13 and the arc-shaped portion 52, the annular groove 13 is not damaged or particles are generated.
[0038]
Since particles are inevitably generated in plasma processing equipment that uses conventional electromagnetic shielding materials, it is necessary to start the operation of the plasma processing equipment after removing the particles, until the processing work is restarted. However, such problems can be solved by using the electromagnetic shielding material 40 of the above-described embodiment.
[0039]
【The invention's effect】
In the electromagnetic shielding material according to the present invention, the opening / closing piece of the conductive covering material can be elastically opened and closed by the elastic core material disposed therebetween, and the members on both sides with which the conductive covering material abuts, without a gap in a wide area. As a result, a good electrical conduction state can be formed by reliable contact, so that an excellent electromagnetic shielding function can be exhibited.
Since the contact between the conductive jacket material and the members on both sides is not intermittent point contact or local contact but surface contact with a sufficient area, repeat the operation of opening and closing the members on both sides. Also, the conductive covering material rarely scrapes or damages the members on both sides and generates fine particles. The electrical contact over a large area is obtained, so that even if the contact pressure is low, the contact resistance is small and a good conduction state can be achieved.The low contact pressure allows the conductive covering material to scrape or damage the members on both sides Or less.
[0040]
Since the elastic core material is covered with the conductive covering material, direct contact with a plasma gas or the like that degrades the elastic core material is prevented, so that the elastic core material can be prevented from deteriorating with time. As a result, an appropriate contact state and a good electrical conduction state between the conductive outer cover material and the members on both sides due to the elastic repulsion of the elastic core material can be maintained for a long time.
[Brief description of the drawings]
FIG. 1 is a cross-sectional structural view of a plasma processing apparatus using an electromagnetic shielding material according to an embodiment of the present invention.
FIG. 2 is a sectional view of an electromagnetic shielding material.
FIG. 3 is a cross-sectional view showing a mounted state (a) and a used state (b) of the electromagnetic shielding material.
[Explanation of symbols]
10 Plasma processing equipment
12 processing room
13 Groove
14 Lid
15 Groove
20 Electromagnetic shielding material
30 hermetic sealing material
40 elastic core material
50 Conductive jacket material
51 Closing piece
52 arc-shaped part
54 Extension
56 connection

Claims (4)

An electromagnetic shielding material that performs an electromagnetic shielding function by being attached to a concave groove provided in one member at a place where a pair of members face each other so as to be able to contact and separate,
A conductive outer cover material having a pair of opening and closing pieces which are made of a conductive material, one end of which is connected in the cross-sectional shape and the other end of which is openably and closably opposed at intervals.
An electromagnetic shield material comprising: an elastic core material which is sandwiched between opening and closing pieces of the conductive outer cover material and is easily elastically deformed. The opening and closing piece of the conductive covering material has an arc-shaped portion having an arc shape having a curvature radius larger than the curvature radius of the elastic core material at a contact point with the elastic core material. The electromagnetic shielding material according to claim 1, further comprising: an extending portion that abuts and extends in parallel, and a connecting portion that connects the opening and closing pieces at one end of the extending portion. The elastic core material is made of an elastic material selected from the group consisting of fluorine rubber and silicone rubber,
The conductive covering material is a pair of open / close formed of a thin plate having a thickness of 0.05 to 0.20 mm and made of a conductive metal material selected from the group consisting of stainless steel, titanium alloy, aluminum alloy, copper alloy, Hastelloy alloy, and Inconel alloy. The electromagnetic shielding material according to claim 1, wherein the pieces are connected by welding at one end of the cross-sectional shape. A shield device disposed at a position where a pair of members face each other so as to be able to contact and separate,
A first concave groove provided in any one of the members at the facing portion,
An airtight shield material that is mounted in the first concave groove of the one member and contacts the other member to perform an airtight sealing function;
A second groove provided on one of the members adjacent to the first groove;
A shield device comprising: the electromagnetic shielding material according to any one of claims 1 to 3, which is mounted in the second groove of the one member and abuts on the other member to perform an electromagnetic shielding function.

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